require 'rational'
module ActiveSupport #:nodoc:
module CoreExtensions #:nodoc:
module DateTime #:nodoc:
# Enables the use of time calculations within DateTime itself
module Calculations
# Seconds since midnight: DateTime.now.seconds_since_midnight
def seconds_since_midnight
self.sec + (self.min * 60) + (self.hour * 3600)
end
# Returns a new DateTime where one or more of the elements have been changed according to the +options+ parameter. The time options
# (hour, minute, sec) reset cascadingly, so if only the hour is passed, then minute and sec is set to 0. If the hour and
# minute is passed, then sec is set to 0.
def change(options)
::DateTime.civil(
options[:year] || self.year,
options[:month] || self.month,
options[:mday] || self.mday,
options[:hour] || self.hour,
options[:min] || (options[:hour] ? 0 : self.min),
options[:sec] || ((options[:hour] || options[:min]) ? 0 : self.sec),
options[:offset] || self.offset,
options[:start] || self.start
)
end
# Uses Date to provide precise Time calculations for years, months, and days. The +options+ parameter takes a hash with
# any of these keys: :months, :days, :years.
def advance(options)
d = ::Date.new(year + (options.delete(:years) || 0), month, day)
d = d >> options.delete(:months) if options[:months]
d = d + options.delete(:days) if options[:days]
change(options.merge(:year => d.year, :month => d.month, :mday => d.day))
end
# Returns a new DateTime representing the time a number of seconds ago
# Do not use this method in combination with x.months, use months_ago instead!
def ago(seconds)
self.since(-seconds)
end
# Returns a new DateTime representing the time a number of seconds since the instance time
# Do not use this method in combination with x.months, use months_since instead!
def since(seconds)
self + Rational(seconds, 86400)
end
alias :in :since
# Returns a new DateTime representing the time a number of specified months ago
def months_ago(months)
months_since(-months)
end
def months_since(months)
year, month, mday = self.year, self.month, self.mday
month += months
# in case months is negative
while month < 1
month += 12
year -= 1
end
# in case months is positive
while month > 12
month -= 12
year += 1
end
max = ::Time.days_in_month(month, year)
mday = max if mday > max
change(:year => year, :month => month, :mday => mday)
end
# Returns a new DateTime representing the time a number of specified years ago
def years_ago(years)
change(:year => self.year - years)
end
def years_since(years)
change(:year => self.year + years)
end
# Short-hand for years_ago(1)
def last_year
years_ago(1)
end
# Short-hand for years_since(1)
def next_year
years_since(1)
end
# Short-hand for months_ago(1)
def last_month
months_ago(1)
end
# Short-hand for months_since(1)
def next_month
months_since(1)
end
# Returns a new DateTime representing the "start" of this week (Monday, 0:00)
def beginning_of_week
days_to_monday = self.wday!=0 ? self.wday-1 : 6
(self - days_to_monday).midnight
end
alias :monday :beginning_of_week
alias :at_beginning_of_week :beginning_of_week
# Returns a new DateTime representing the start of the given day in next week (default is Monday).
def next_week(day = :monday)
days_into_week = { :monday => 0, :tuesday => 1, :wednesday => 2, :thursday => 3, :friday => 4, :saturday => 5, :sunday => 6}
((self + 7).beginning_of_week + days_into_week[day]).change(:hour => 0)
end
# Returns a new DateTime representing the start of the day (0:00)
def beginning_of_day
change(:hour => 0)
end
alias :midnight :beginning_of_day
alias :at_midnight :beginning_of_day
alias :at_beginning_of_day :beginning_of_day
# Returns a new DateTime representing the end of the day (23:59:59)
def end_of_day
change(:hour => 23, :min => 59, :sec => 59)
end
# Returns a new DateTime representing the start of the month (1st of the month, 0:00)
def beginning_of_month
change(:mday => 1,:hour => 0, :min => 0, :sec => 0)
end
alias :at_beginning_of_month :beginning_of_month
# Returns a new DateTime representing the end of the month (last day of the month, 0:00)
def end_of_month
last_day = ::Time.days_in_month( self.month, self.year )
change(:mday => last_day,:hour => 0, :min => 0, :sec => 0)
end
alias :at_end_of_month :end_of_month
# Returns a new DateTime representing the start of the quarter (1st of january, april, july, october, 0:00)
def beginning_of_quarter
beginning_of_month.change(:month => [10, 7, 4, 1].detect { |m| m <= self.month })
end
alias :at_beginning_of_quarter :beginning_of_quarter
# Returns a new DateTime representing the start of the year (1st of january, 0:00)
def beginning_of_year
change(:month => 1,:mday => 1,:hour => 0, :min => 0, :sec => 0)
end
alias :at_beginning_of_year :beginning_of_year
# Convenience method which returns a new DateTime representing the time 1 day ago
def yesterday
self - 1
end
# Convenience method which returns a new DateTime representing the time 1 day since the instance time
def tomorrow
self + 1
end
end
end
end
end
